package jianzhi_offer;

public class _24_复杂链表的复制 {
    public static void main(String[] args){
        _24_复杂链表的复制 test = new _24_复杂链表的复制();
        RandomListNode r1 = new RandomListNode(1);
        RandomListNode r2 = new RandomListNode(2);
        RandomListNode r3 = new RandomListNode(3);
        RandomListNode r4 = new RandomListNode(4);
        r1.next = r2;
        r2.next = r3;
        r3.next = r4;
        r1.random = r3;
        r3.random = r2;
        RandomListNode newR = test.Clone(r1);
        while(newR != null){
            System.out.println(newR.label);
            newR = newR.next;
        }
    }

    public RandomListNode Clone(RandomListNode pHead)
    {
        if(pHead == null) {
            return null;
        }

        RandomListNode currentNode = pHead;
        //1、复制每个结点，如复制结点A得到A1，将结点A1插到结点A后面；
        while(currentNode != null){
            RandomListNode cloneNode = new RandomListNode(currentNode.label);
            RandomListNode nextNode = currentNode.next;
            currentNode.next = cloneNode;
            cloneNode.next = nextNode;
            currentNode = nextNode;
        }

        currentNode = pHead;
        //2、重新遍历链表，复制老结点的随机指针给新结点，如A1.random = A.random.next;
        while(currentNode != null) {
            currentNode.next.random = currentNode.random==null?null:currentNode.random.next;
            currentNode = currentNode.next.next;
        }

        //3、拆分链表，将链表拆分为原链表和复制后的链表
        currentNode = pHead;
        RandomListNode pCloneHead = pHead.next;
        while(currentNode != null) {
            RandomListNode cloneNode = currentNode.next;
            currentNode.next = cloneNode.next;
            cloneNode.next = cloneNode.next==null?null:cloneNode.next.next;
            currentNode = currentNode.next;
        }

        return pCloneHead;
    }
}
